The present invention relates to an internal catheter for insertion into the urethra of a patient and to a catheter guide for effecting such insertion, More particularly, the present invention relates to an indwelling catheter specifically adapted for treating obstruction of the prostatic urethra and to a catheter guide, for flushing the patient's urinary tract and for the insertion and positioning of the catheter therewithin. The invention further relates to a method of inserting and positioning an indwelling catheter in the urinary tract of a patient using the guide of the present invention.
Benign prostate hyperplasia (BPH) is a condition wherein enlargement of the prostate gland constricts and blocks the portion of the urethra traversing the prostate (i.e., the prostatic urethra) and leads to difficulties in normal urination.
BPH is typically treated by using surgical procedures such as trans urethral resection of the prostate (TURP) or preferably by non-surgical procedures, such as thermal ablation of the prostate, a procedure which typically employs a catheter supplemented with a balloon head positioned within the prosthetic urethra, in which balloon heated water is recirculated.
Following a thermal ablation procedure, temporary blockage of the prostatic urethra is usually experienced due to extensive swelling and edema formation. Proper healing of the prostatic tissue and long-term urination of the patient requires the removal of the ablation balloon catheter and the subsequent insertion of a drainage catheter into the prostatic urethra.
Several types of drainage catheters are known. One type includes tubing leading from the bladder through the entire length of the urinary tract to the outside. Such catheters, beside being highly uncomfortable, suffer from two major limitations. First, such catheters do not allow voluntary urination. Second, upon prolonged installation, they frequently cause urinary tract infections.
Another type includes indwelling catheters which are typically used when long catheterizing periods are required, such as following BPH elimination treatment, during the healing of the tissues damaged by the treatment. During this time period the healing and scarring of the prostate tissue around the catheter ensures that the prostatic urethra remains dilated after the catheter is removed.
Presently, there exist various indwelling catheters for insertion into the patient's urinary tract for enabling effective drainage of fluids and tissue particles following a prostate unblocking procedure.
Examples of such indwelling catheters are disclosed in U.S. Pat. Nos. 3,811,450; 5,176,626; and 5,514,178.
An indwelling catheter employed in treating and unblocking of a prostatic urethra must meet several requirements. The catheter must have a portion which traverses the blocked prostatic urethra. The catheter must allow the patient control over urination, either biologically (voluntary sphincter control) or mechanically (e.g., a mechanical valve). In addition, an indwelling catheter must be appropriately positioned and anchored, such that no permanent movement of the device is experienced during service.
To meet the above requirements, presently employed indwelling catheters have incorporated several configurations of inflatable balloons, for anchoring and appropriately positioning the catheter within the patient's urinary tract. Such configurations typically include balloons, such as in Folley catheters, in which a positioning and anchoring balloon is positioned within the patient's bladder and is anchored against the inner-wall of the bladder opening, or ring type balloons which are inflated against the prostatic urethra and serve to both unblock the prostatic urethra and establish a tract for urination. Furthermore, balloons which are carried on the catheter itself, or alternatively on a catheter guide used for its insertion and positioning, serve for appropriately inserting and positioning the catheter by functioning as “insertion halters” and as “position reference” when halted by the patient's sphincter.
Other anchoring methods, as demonstrated by the transurethral bridge feature of the catheter produced by Boston Scientific (known as TRESTLE), a schematic depiction of which is shown in FIG. 5, also exist.
In this configuration, the placement of two tubes, interconnected by a wire, on opposite sides of the sphincter anchors the catheter against longitudinal displacement, and also allows patient voluntary control over urination.
Limitations are inherent to the catheters of the above mentioned designs. For example, some catheters are constructed such that they traverse the sphincter region of the urethra, not allowing for sphincter closure and thus necessitating the use of a valved line for urination control. These catheters are further limited in such that the urination line which leads from the bladder to the outside environment is often the cause of urinary tract infections, which necessitate the removal of the catheter, followed by antibiotic treatment and repositioning of a new catheter, causing great discomfort to the patient. On the other hand, catheters employing transurethral bridges often tend to proximally displace within the urethra when the patient urinates, due to a relief in the anchoring of the catheter upon sphincter dilation.
Additionally, positioning of a catheter via a sphincter balloon can often be difficult and time consuming, whereas positioning of a catheter via a bladder balloon often necessitates a more complex guide and catheter system.
There is thus a widely recognized need for, and it would be highly advantageous to have, an indwelling urethral catheter devoid of the above limitations. The catheter according to the present invention can be used for drainage of fluids and tissue particles through the patient's prostatic urethra following a non-surgical medical procedure such as thermal ablation of the prostate, wherein a long-term indwelling catheter is needed, while allowing voluntary control over urination.